1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * thermal_helpers.c - helper functions to handle thermal devices 4 * 5 * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com> 6 * 7 * Highly based on original thermal_core.c 8 * Copyright (C) 2008 Intel Corp 9 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> 10 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/sysfs.h> 16 #include <linux/device.h> 17 #include <linux/err.h> 18 #include <linux/slab.h> 19 #include <linux/string.h> 20 21 #include <trace/events/thermal.h> 22 23 #include "thermal_core.h" 24 25 int get_tz_trend(struct thermal_zone_device *tz, int trip) 26 { 27 enum thermal_trend trend; 28 29 if (tz->emul_temperature || !tz->ops->get_trend || 30 tz->ops->get_trend(tz, trip, &trend)) { 31 if (tz->temperature > tz->last_temperature) 32 trend = THERMAL_TREND_RAISING; 33 else if (tz->temperature < tz->last_temperature) 34 trend = THERMAL_TREND_DROPPING; 35 else 36 trend = THERMAL_TREND_STABLE; 37 } 38 39 return trend; 40 } 41 EXPORT_SYMBOL(get_tz_trend); 42 43 struct thermal_instance * 44 get_thermal_instance(struct thermal_zone_device *tz, 45 struct thermal_cooling_device *cdev, int trip) 46 { 47 struct thermal_instance *pos = NULL; 48 struct thermal_instance *target_instance = NULL; 49 50 mutex_lock(&tz->lock); 51 mutex_lock(&cdev->lock); 52 53 list_for_each_entry(pos, &tz->thermal_instances, tz_node) { 54 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { 55 target_instance = pos; 56 break; 57 } 58 } 59 60 mutex_unlock(&cdev->lock); 61 mutex_unlock(&tz->lock); 62 63 return target_instance; 64 } 65 EXPORT_SYMBOL(get_thermal_instance); 66 67 /** 68 * thermal_zone_get_temp() - returns the temperature of a thermal zone 69 * @tz: a valid pointer to a struct thermal_zone_device 70 * @temp: a valid pointer to where to store the resulting temperature. 71 * 72 * When a valid thermal zone reference is passed, it will fetch its 73 * temperature and fill @temp. 74 * 75 * Return: On success returns 0, an error code otherwise 76 */ 77 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 78 { 79 int ret = -EINVAL; 80 int count; 81 int crit_temp = INT_MAX; 82 enum thermal_trip_type type; 83 84 if (!tz || IS_ERR(tz) || !tz->ops->get_temp) 85 goto exit; 86 87 mutex_lock(&tz->lock); 88 89 ret = tz->ops->get_temp(tz, temp); 90 91 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { 92 for (count = 0; count < tz->trips; count++) { 93 ret = tz->ops->get_trip_type(tz, count, &type); 94 if (!ret && type == THERMAL_TRIP_CRITICAL) { 95 ret = tz->ops->get_trip_temp(tz, count, 96 &crit_temp); 97 break; 98 } 99 } 100 101 /* 102 * Only allow emulating a temperature when the real temperature 103 * is below the critical temperature so that the emulation code 104 * cannot hide critical conditions. 105 */ 106 if (!ret && *temp < crit_temp) 107 *temp = tz->emul_temperature; 108 } 109 110 mutex_unlock(&tz->lock); 111 exit: 112 return ret; 113 } 114 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 115 116 void thermal_zone_set_trips(struct thermal_zone_device *tz) 117 { 118 int low = -INT_MAX; 119 int high = INT_MAX; 120 int trip_temp, hysteresis; 121 int i, ret; 122 123 mutex_lock(&tz->lock); 124 125 if (!tz->ops->set_trips || !tz->ops->get_trip_hyst) 126 goto exit; 127 128 for (i = 0; i < tz->trips; i++) { 129 int trip_low; 130 131 tz->ops->get_trip_temp(tz, i, &trip_temp); 132 tz->ops->get_trip_hyst(tz, i, &hysteresis); 133 134 trip_low = trip_temp - hysteresis; 135 136 if (trip_low < tz->temperature && trip_low > low) 137 low = trip_low; 138 139 if (trip_temp > tz->temperature && trip_temp < high) 140 high = trip_temp; 141 } 142 143 /* No need to change trip points */ 144 if (tz->prev_low_trip == low && tz->prev_high_trip == high) 145 goto exit; 146 147 tz->prev_low_trip = low; 148 tz->prev_high_trip = high; 149 150 dev_dbg(&tz->device, 151 "new temperature boundaries: %d < x < %d\n", low, high); 152 153 /* 154 * Set a temperature window. When this window is left the driver 155 * must inform the thermal core via thermal_zone_device_update. 156 */ 157 ret = tz->ops->set_trips(tz, low, high); 158 if (ret) 159 dev_err(&tz->device, "Failed to set trips: %d\n", ret); 160 161 exit: 162 mutex_unlock(&tz->lock); 163 } 164 EXPORT_SYMBOL_GPL(thermal_zone_set_trips); 165 166 void thermal_cdev_update(struct thermal_cooling_device *cdev) 167 { 168 struct thermal_instance *instance; 169 unsigned long target = 0; 170 171 mutex_lock(&cdev->lock); 172 /* cooling device is updated*/ 173 if (cdev->updated) { 174 mutex_unlock(&cdev->lock); 175 return; 176 } 177 178 /* Make sure cdev enters the deepest cooling state */ 179 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 180 dev_dbg(&cdev->device, "zone%d->target=%lu\n", 181 instance->tz->id, instance->target); 182 if (instance->target == THERMAL_NO_TARGET) 183 continue; 184 if (instance->target > target) 185 target = instance->target; 186 } 187 188 if (!cdev->ops->set_cur_state(cdev, target)) 189 thermal_cooling_device_stats_update(cdev, target); 190 191 cdev->updated = true; 192 mutex_unlock(&cdev->lock); 193 trace_cdev_update(cdev, target); 194 dev_dbg(&cdev->device, "set to state %lu\n", target); 195 } 196 EXPORT_SYMBOL(thermal_cdev_update); 197 198 /** 199 * thermal_zone_get_slope - return the slope attribute of the thermal zone 200 * @tz: thermal zone device with the slope attribute 201 * 202 * Return: If the thermal zone device has a slope attribute, return it, else 203 * return 1. 204 */ 205 int thermal_zone_get_slope(struct thermal_zone_device *tz) 206 { 207 if (tz && tz->tzp) 208 return tz->tzp->slope; 209 return 1; 210 } 211 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 212 213 /** 214 * thermal_zone_get_offset - return the offset attribute of the thermal zone 215 * @tz: thermal zone device with the offset attribute 216 * 217 * Return: If the thermal zone device has a offset attribute, return it, else 218 * return 0. 219 */ 220 int thermal_zone_get_offset(struct thermal_zone_device *tz) 221 { 222 if (tz && tz->tzp) 223 return tz->tzp->offset; 224 return 0; 225 } 226 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 227